[time 510] Re: [time 509] Observation models


Stephen P. King (stephenk1@home.com)
Sun, 01 Aug 1999 22:31:42 -0400


Dear Matti,

        I am working on a big post on Pratt's work. I'll shorten this one a
lot....

Matti Pitkanen wrote:
snip
[SPK]
> > But is it not true that symbols are information when we think of them
> > as having a "meaning" but are material configurations when we think of
> > quantities such as charge, mass, spin, etc. ? A robot has all of its
> > behavior predetermined, it has not free-will!
[MP]
> I would say that symbols are more: they are conscious subselves
> representing someting (in external world). Selves as robots
> is of course the great failure of AI. The capture of basic
> hierarchical structures of cognitive processing and mechnization
> of logical thinking is its victory and also quantum theories
> of cs must be able to reproduce this part of computationalism
> (neuroscience and cognitive psychology rely strongly on computational
> approach).

        Have you read Howard Pattee's papers?
http://ssie.binghamton.edu/~pattee/ I think that you would find them
interesting! :-)

snip

> > [MP]
> > > I am not sure what you meant with 'the ordering of quantum jumps is not an
> > > a priori given'. It is! There is only ordered heap of ticks with new
> > > tickes added on this heap 'all the time'. What is not given except in
> > > statistical sense, is the ordering of psychological times associated with
> > > quantum jumps for a given self: psychological time can also decrease
> > > occasionally. The ordering of quantum jumps is what gives subjective
> > > time absolute arrow and induces arrow of psychological time.
> > > In second time scale this arrow is absolute. 10^40 events make
> > > statistics excellent!
[SPK]
> > I am talking about the order of the "ticks", like how would they be
> > labeled 1, 2, 3, ... The "heap" of then "exists" for sure, but the order
> > in which individual q-jumps are taken from the heap is, I am arguing,
> > not a priori given.
>
> [MP] It is. The point is that jumps are pairs
>
> m-->n n--p p--> s.
>
> Since the *initial* state of next jump is the *final* state of previous
> jump natural ordering of quantum jumps is unavoidable.

        Sure, I understand that, but the n and s are chosen from the heap, I
think, based on the logical implications that such choices would have. I
will explain this further in my Pratt post...
 
snip
> > [MP]
> > > This would be true if you would quantize metric of spacetime just as it
> > > is quantized in GRT. In TGD nothing like this is attempted.
> > >
> > > a) Association X^3-->X^4(X^3) *fixing geodesics* but is by no means in
> > > conflict with uncertainty principle since the construction of
> > > configuration space spinor fields reduces to the construction of their
> > > values on the space of 3-surfaces located on lightcone boundary times
> > > CP_2. Values of configuration space spinor fields elsewhere are fixed
> > > by Diff^4 invariance.
[SPK]
> > But, what about the problem that Hitoshi points out that Diff^4
> > invariance prohibits the construction of clocks, and without clocks it
> > is impossible to measure time.
[MP]
> Why would one need this highly idealized continuous network of clocks? I
> think that it is quite too much! All what is needed that theory allows
> conscious selves able to have sensory experience about how some purely
> classical oscillatory processes proceed. Cognitive spacetime sheets allow
> this.
>
> If one requires that spacetime has magic ability to measure the
> coordinates of its points (not only time) one encounters also the problem:
> which coordinates it uses?

        Umm, I am saying that space-time is "in our head", is is a framing of
observations. There is no need for "continuous network of clocks" or
"magic ability" of space-time to measure the coordinates of its points,
the particular coordinate system that an observer uses is chosen by the
logical entailment of the history of such... More in the Pratt post...
 
snip
> > > c) Uncertainty principle forces states to be *superpositions of
> > > spacetime surfaces X^4(X^3)* but does not make the concept of
> > > classical goeodesic nonsensical.
[SPK]
> > After reading Prigogine's work I am not so sure! He points out that it
> > is impossible to define individual trajectories, e.g. geodesics...
[MP]
> Certainly true in standard quantization of general relativity.
> If metric become operator of second quantized theory then
> also the notion of geodesic line becomes very fuzzy. Of course,
> the operator formalism fails down: the highly nonlinear
> formulas of GRT simply do not make sense as operator formulas.

        We bypass this in LS theory...
 
> The key question is: is classical theory only approximation
> of quantum theory or essential part of it. In standard physics
> answer is 'only approximation', in TGD the answer is 'essential
> part of it'. That TGD answer is possible relates directly to
> the hypothesis that spacetimes are 4-surfaces. This
> hypothesis also solves the energy problem of GRT.

        Why can't we just think of classical theory as a useful model for
dealing with situations where velocities and energies are low? It is
just a way of thinking about the world, it is not "the world"!
 
[MP]
> > > Yes. Let me see this from my viewpoint. I have definition of self as
> > > quantum subsystem: the geometric definition
> > > underlies it. The event horizons associated with wormholes (metric
> > > determinant vanishes since metric changes from 1-1-1-1 to -1-1-1-1
> > > signature are natural boundaries of selves.
[SPK]
> > I do not understand your thinking here. How do you know that it is a
> > metric chance involved in the boundary of a self?
[MP]
> The surface at which signature changes is natural candidate
> for a boundary of self. All what remains inside boundary forms kind of
> causal closure *classically*: geodesics do not lead out.

        Like an event horizon of a black-hole?
 
[MP]
> > > Reading Pinker it becomes clear that AI people also have realized
> > > the importance of competion: otherwise everything would be drowned
> > > floodwave caused by by combinatorial explosion. The most interesting
> > > conscious experiences are experienced: this is the fundamental
> > > dynamics of conscious information processing. The decision of winner
> > > in TGD framwork is simple: quantum jumper with maximum entanglment
> > > negentropy gain is the winner.
[SPK]
> > Yes, I agree. Is the number of players competing (in the q-jump)
> > restricted to a finite number?
[MP]
> In principle no.
 
        Sure, in principle the number of LS;s that interact in Hitoshi's theory
is infinite also, I was just trying to think of a small toy model
version...

[MP]
> > > Why I regard it as so important is that it gives direct connection
> > > with quantum measurement theory and is consistent with it. Any principle
> > > which one postulates, must be consistent with QMT: this is highly
> > > nontrivial requirement.
[SPK]
> > The only difficulty is that we must be very careful how we interpret
> > QMT!
[MP]
> QMT reduces in practice to simple rules: final states are eigenstates of
> observables and probabilities for various outcomes are given by Born's
> rule. Every generalization shold produce these well tested rules.

        This also is covered in Pratt's notions...
 
snip
[MP]
> Any action principle does this and without action principles
> there is no physics! It is quite possible that absolute minimization
> problem can be solved exactly. Construction of configuration
> space geometry leads to very strong constraints on initial
> values giving absolute minima. The situation is very much analogous
> to that in Euclidian YM theories, which absolutely minimize
> Euclidian YM action.

        I don't understand "YM"... Could we have a discussion just about
"action principles"?
 
[MP]
> > > No. Induction procedure and projection of CP_2 Kahler
> > > form to spacetime surface is completely unique. The map of
> > > real spacetime surface to p-adic spacetime
> > > surface defines observer dependent spacetime as a p-adic version of
> > > spacetime surface satisfying p-adic field equation (absolute minimization
> > > of Kahler action).
[SPK]
> > Ok, On this I agree, but it is not what I am asking about! I am
> > thinking about how the minimization of the Kaehler action is not a
> > global action, it is local to the particular observer, thus each
> > observer would have their own "absolute minimization of the Kaehler
> > action", since every observer has their own light-cone structure. I
> > point to a generalization of the principle of equivalence: "every
> > observer always is at rest with respect to their local framing". When
> > interaction occurs between observers the space-time framing is changed
> > by the q-jump, and thus the particular minimization configuration of
> > changed. This is the act of computation that I am thinking of!
[MP]
> In good approximation this is indeed the case. Kahler function
> reduces in good approximation to a sum of Kahler functions associated
> with spacetime sheets representing individual observers. There
> are however small interaction terms involved.

        What is the form of these interaction terms?
 
> The more or less implicit assumption of all physical theories is
> that one can build more complicated solutions from simpler ones
> somehow and that quantities like energy and action are additive
> in this process in good approximation. In linear theories one just
> sums solutions. In nonlinear solvable models one 'sums'
> single soliton solutions. In TGD this building recipe is to glue
> spacetime sheets on spacetime sheets.

        OK, this follows the idea that we can construct complicated mental
models from the combination of many simple ones...
 
snip

Onward,

Stephen



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